function getCookie(c_name) {
    if (document.cookie.length>0){
      c_start=document.cookie.indexOf(c_name + "=");
      if (c_start!=-1){
        c_start=c_start + c_name.length+1;
        c_end=document.cookie.indexOf(";",c_start);
        if (c_end==-1) c_end=document.cookie.length;
        return unescape(document.cookie.substring(c_start,c_end));
      } 
  	}
	return "";
}
function setCookie(c_name,value,expiredays) {
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toGMTString())+";path=/jpw";
}
function clearCookie(name) {  
    setCookie(name, "", -1);  
}
function clearCookies(names) {
	for (var i = 0; i<names.length; i++) {
		setCookie(names[i], "", -1);
	}
}
function checkCookie() {
	username=getCookie('username');
	if (username!=null && username!="") {
		alert('Welcome again '+username+'!');
	}
	else {
  		username=prompt('Please enter your name:',"");
  		if (username!=null && username!="") {
    		setCookie('username',username,365);
    	}
  	}
}